Regulation of the supply of fuel to internal combustion engines



P. won/men: 2,2 REGULATION OF THE SUPPLY OF FUEL 1'0 INTERNAL COMBUSTION ENGINES Oct. 23, 1941.

Filed Jan. 28, 1939 2 Sheets-Sheet 1 E .7 A m e I a 5 W g Q 5M W0 K y R K 5 IJ H m mL U V Y 0% v m e m a Z JM M .L E 3 8 T 6 v m H N K 1 k .M wv'lllti" v /1\ w Oct. 28, 1941. P. L'ORANGE REGULATION OF THE SUPPLY OF FUEL TO INTERNAL COMBUSTION ENGINES Filed Jan. 28, 1939 2 Sheets-Shea; 2

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Patented oer 28, 1941 Q 2,260,688

UNITED STATES PATENT OFFICE REGULATION THE SUPPLY OI FUEL '10 1 INTERNAL COMBUSTION ENGINES Prosper 120mm, Stuttgart-Feuerbacll, Germany; Rudolf LOrango executor of theestate of said Prosper LOrange, deceased Application January 28, 1939, Serial 'No. 253,452

7 In Germany June 4, 1935 4 Olaims- (CL 123-140) This invention relates to the regulation of the would be too small at highengine speeds and too supply of fuel to internal combustion engines in great at low engine speeds. which the combustible mixture is formed exter- Further according to the present invention, nally of the engine. therefore, surplus fuel is returned to the pump The automatic intake of fuel from a carbu- 5 through an aperture the magnitude of which is rettor suffers from many disadvantages, which, increased or reduced in the same proportion as due to the fact that the fuel feed to the supply the magnitude of the" throttle aperture leading nozzle is dependent upon the liquid level mainto the injection nozzle is reduced or increased. tained by a float, arise particularly in cases This effect could be obtained by individually conwhere the engine is required to operate in any trolling each of the two apertures by means of position, for examplein an inverted position. the negative pressure in the induction passage. It has therefore been proposed to employ a Preferably, however, for the sake of simplicity, pump fol-the supply of fuel in order to obtain both apertures are controlled by a diaphragm or a more positive feed, but in that case, dlillculties its equivalent controlled in accordance with the arise in the regulation of the fuel supply in ennegative pressure prevailing for the time being gines regulated by varying the quantity of fuel in the induction passage, and effecting the consupplied, due to the fact that the quantity of trol of-the fuel supply, for example by displacing fuel supplied must be adapted both to the ena control piston which positively controls one gine speed and to the quantity of air determined aperture and negatively controls the other aperby the throttling of the air supply. '20 ture.

If the output of the fuel supply pump itself is In order that the invention may be clearly uninfluenced by negative pressure in the intake derstood and readily carried into eifect, referpassage of the engine, it is necessary to construct ence will now be made to the constructional cmthe pump in the manner of the iniection pumps bodiments of the invention illustrated by way of used in engines in which the mixture is internally example in the accompanying drawings, 'in formed; that is to say, the pump output must which-- be capable of fine regulation, whereby unneces- Figure 1 illustrates diagrammatically a comsary complications are caused. In the case of plete fuel supply regulating installation in acmulti-cylinder engines in which the mixture is cordance with the invention: externally formed, the fuel must be injected by Figure 2 illustrates in vertical section a modione nozzle into an intake passage common to fled form of the regulating device illustrated in all or a number of the cylinders, and the present Figure 1;

invention providesafuel feeding arrangement, ap- Figure 3 is a view similar to Figure 2, but ilplicable under-such circumstances, which renders lustrates a further modification of the re ating it possible to dispense with regulation of the outdevice;

put of the pump and therefore to employ a" sup- Figure 4 is a section taken on the line x-x ply pump of a simple character such as has hithof Figure 3; erto been employed as a feed pump; Figure 5 illustrates in vertical section another According to the invention fuel from a presform of the regulating device; and

sure chamber supplied by a pump ispassed to the 40 Figure 6 illustrates in vertical section a furengine induction'passage, for the purpose of the ther embodiment of the regulating device. regulation, through a throttle aperture the cross- Referring to Figure 1 of the drawings, the insection of which isadiusted proportionately to stallation is illustrated as applied to an engi e the negative pressure in a region of the inducintake pipe A leading to a series of three cylintion passage between the throttle valve and the ders and provided with a throttle valve B, and a engine, surplus fuel being returned to the sucfuel injection nouie C supplied with fuel by tion side of the pump: a way of a pipe D connected to a regulating device If the surplus fuel were returned to the suc-' E. The casing of the regulator it contains three tion side of the supply pump through a throttle chambers, the lowermost one of which is connectaperture of constant magnitude, the pressure of ed to the nozzle 0 through the pipe D, whilst the fuel supplied to the engine would be too great the centre chamber is connected by a pipe F to at high engine speeds and too small at low engine the pressure chamber of a pump E and the On the other hand, if the fuel were reuppermost chamber is connected by a pipe G to turnedtothe pump throughan aperture throttled the suction chamber of the pump B. All the by a spring-loaded valve, the pressure of thefuel chambers are traversed by a control piston J,

which has a longitudinalrecess at J oisuch length that when the piston is in its mid-position the upper limiting edge or the recess projects beyond the edge oi thepiston guideby a distance equal to that by which the lower limiting edge of the recess extends downwards below the edge 01 the guide.

The piston J is controlled by a diaphragm K attached to the upper end of the piston and loaded by a spring L. The diaphragm is enclosedinacasingprovidingaspaceabovethe diaphragm which communicates with the induction. pipe A through a pipe M, and a space below the diaphragm communicating for example with the atmosphere.

The diphragm spring Lissoadjustedthat when the negative pressure in the inducflon pipe A is 01 minimum value the piston is moved to its maxi- .mum extent inthe downwarddirectionsoasto s increase the size of the aperture through which the fuel is supplied to the nomle C and approximately to close the upper aperture through which surplus fuel is returned to the suction chamber of the pump.

When the negative pressure in the induction pipe 4 increases, the diaphragm K is lifted by the air pressure against the action of the spring L and the aperture through which the supply to the nozzle takes place is so reduced as to have a minimum value, which is practically zero, when the negative pressure is greatest. Accordingly, the upper aperture through which surplus fuel is returned to the suction space of the pump is opened at the same time so that it is greatest during no-load operation and the sum of the cross-sections of the two apertures always remains approximately constant.

The total throttling oi the fuel supply is thus so great that the influence oi the throttling eilfect of the injection nozzle is negligible. For example', the throttling due to the regulating device may correspond to 3 atmospheres at the maximum engine speed-whereas that of the name sure chamber and the suction chamber'respectively or the pump, whilst the air intake pipe or the engine is connected to the port IV.

The chamber in which the corrugated tube K is enclosed communicates with the atmosphere u h po s Q, Q-

Figures 3 and 4 illustrate a construction in which the negative pressure in the intake pipe of the engine acts from below on the corrugated tube K and the atmospheric air pressure, or a constant pressure from a specially connected chamber, acts thereon from above. In this case the port I of the casing E is connected to the injection nozzle and the ports II and III respec- 'tively to the. pressure chamber and to the suction chamber of the pump, whilst the air intake pipe of the engine is connected to the port IV. The port V, when the cap R is mounted, is connected to a chamber maintained at constant pressure.

In this construction the control piston J is ground in the bush M and has a fine slot J, the upper and lower limiting edges of which cooperate with control edges formed by the edges of apertures S and T in order to control the size of the apertures S and T in proportion to the lift. The lift is eii'ected by the movement of the is similar in construction to that illustrated in may only amount-to about 60 centimetres oi water column. Ii it is desired that the fuel supply pressure should be greater, the liquid flowing back to the pump may also be throttled between the regulator and the suction chamber of! the pump. v

In the construction illustrated in Figure 2, in which the diaphragm is in the i'orm of a corrugated tube K, an accurately calibrated bush M -isflttedinacasingE,andacontrolpistonJ having a Part J or reduced cross-section is secured at its upper end to the corriigated tube K and arranged slidably in the said bush M The said corrugated tube K is tightly connected to a cover N screwed into the casing E, the said cover having a threaded bo're which receives at its lower end a bored spring abutment O and at its upper end a cap P tor connection to the tube extending to the air intake pipe of the engine. The said screw cap P and spring abutment O are both engaged by the same thread in the cover N. A loading spring L is arranged to bear against the spring abutment O, the said spring being so designed as to be expanded when the 1 Figure 3, and the same reference numerals have been employed to designate similar parts in these figures. In Figure 5, however, the control piston J is of reduced diameter over a portion of its length and the upper and lower limiting edges of this reduced portion co-operate with line incisions S and '1', formed at the ends of the apertures S and T respectively, in order to control the size of the said apertures S and T in proportion to the lift.

Figure 6 illustrates aiurther modification of the construction illustrated in Figure 3. In Figure 6, the control piston J is Hollow and its bore communicates with two fine bores J and J which co-operate with control edges formedby the edges of the. apertures S and T, in order to control the sizes of the said apertures S and T in proportion to the lift. 'I'heport II, in this ture to said engine;,a source oi fuel; a fuel injection nozzle in said manifold in advance of the throttle valve therein; a pump for supplying fuel from said source to said nozzle; a regulating device positioned between said nozzle and said pump and including a casing having-an inlet connectedto the discharge side of the pump, a first outlet connected to said nozzle, a second outlet connected to said source of fuel, a single tion nozzle and the ports I! and III to the 91-5.. reciprocable valve member within said casing having a valve part operable upon reciprocation of said valve member to controlthe flow of fuel from said inlet to said first outlet to regulate the fiow of fuel from said pumpto said nozzle and a valve part operable upon reciprocation of said valve member to control the flow of fuel from said inlet to said second outlet to regulate the flow of fuel from the pump to said source, and a pressure-responsive device connected to said valve member for actuating the same; and a connection between one side of said pressureresponsive device and the intake manifold at a point in said manifold between the throttle valve and engine, 'the other side of said pressure-responsive device communicating with a source of constant pressure, whereby thevalve member and consequently the supply of fuel from the pump to the nozzle and to the source are simultaneously controlled in accordance with variations in the pressure within the manifold at the point of connection between said manifold and said pressure-responsive device.

2. A fuel supply system for internal combustion engines comprising an intake manifold for said engine; a throttle valve within said manifold for controlling the flow of combustible mixture to said engine; a source of fuel; a fuel injection nozzle in said manifold in advance of the throttle valve therein; a pump for supplying fuel from said source to said nozzle; a regulating device positioned between said nozzle and said pump and including a casing having an inlet connected to the discharge side of the pump, a

' first outlet connected to said nozzle, a second.

outlet connected tosaid source of fuel, a single reciprocable valve member within said casing having a valve part operable upon reciprocation of said valve' member-to control the flow of fuel from said inlet to said first outlet to regulate the flow of fuel from said pump to said nozzle and a valve part operable upon reciprocation of said valve member to control the flow of fuel from said inlet to said second outlet to regulate the flow of fuel from the pump to said supply, a pressure-responsive device connected to said valve member for actuating the same, and an expansion spring bearing against one side of said pressure-responsive device for normally maintaining the flow of fuel from said pump to said nozzle and interrupting the flow of fuel from said pump to said source; and a connection between that side of the pressure-responsive device on which said spring is effective and the intake manifold at a point in said manifold. between the throttle valve and the engine, the opposite side of said pressure-responsive device communicating with a source of constant pressure, whereby the valve member and consequently the supply of fuel from the pump to the nozzle and to the source are simultaneously controlled in accordance with variations in the pressure within the manifold at the point of connection between said manifold and said pressure-responsive device.

3, A fuel supply system for internal combustion engines as defined in claim 1 in which the reciprocable valve member is actuated by the pressure-responsive device to control the first and second outlets simultaneously and in inverse proportion.

4. A fuel supply system for internal combustion engines comprising an intake manifold for said engine; a throttle valve within said manifold for controlling the flow of combustible mixture to said engine; a source of fuel; a fuel injection nozzle in said manifold in advance of the throttle valve therein; a pump for supplying fuel from said source to said nozzle; a regulating device positioned between said nozzle and said pump and including a casing having a chamber therein communicating with a source of constant pressure, said casing having an inlet connected to the discharge side of the pump, a first outlet connected to said nozzle, a second outlet connected to said source of fuel, a single reciprocable valve member within said casing having a valve part operable upon reciprocation of said valve member to control the flow of fuel from said inlet to'said first outlet to regulate the flow of fuel from said pump to said nozzle and a valve part operable upon reciprocation of said valve member to control the flow of fuel from said inlet to said second outlet to regulate the flow of fuel from the pump to said supply, and a pressure-responsive device connected to said valve member for actuating the same, said pre sure-responsive device being positioned within the chamber in said casing with one side thereof responsive to the constant pressure within said chamber; and a connection between the opposite side of; said pressure-responsive device and the intake manifold at a point in said manifold manifold at the point of connection between said manifold and said pressure-responsive device.

PROSPER LORAN GE. 

